Yes, they certainly need a supplement if there's no algae in the tank or they might move on to other plants too.
However, mine do get algae wafers, etc. and they still mowed down the J. Moss. Even the Silver Dollars (lawn mowers) in another tank don't chow the stuff the way the SAE's do. :?
However, mine do get algae wafers, etc. and they still mowed down the J. Moss. Even the Silver Dollars (lawn mowers) in another tank don't chow the stuff the way the SAE's do. :?